Study Of Well Pattern Evaluation Method And Application In Extra-high Water Cut Stage

At present the majority of our country's onshore fields have entered high water cut stage and even extra-high water cut stage,but the remaining oil reserve is still very considerable.Well pattern adaptability evaluation has a very important significance to guide well pattern adjustment to improve the oil recovery in this stage Thus,it is very important to put forward a reasonable well adaptability evaluation method for reservoirs in extra-high water cut period to improve the development effect.By introducing the concept of the fluid potential to developed reservoir,the effects of geological and development factors to reservoir are quantified.Then,the definition of reservoir flow field strength is put forward to characterize fluid flow capability in extra-high water cut stage.And the specific calculation method of this parameter in grid systems is studied.Using programming method,the streamline tracing method is realized.O n the basis of the streamline distribution,a new indicator for well pattern adaptability evaluation,the control degree of remaining reserve based on streamline,is defined.According to the water crossing multiple theory of water flooding,flooding potential with certain streamline distribution is calculated.Applying the foregoing theory to the actual reservoir C23 zone,combined with reservoir simulation software,optimization of water injection rate and infill well location of this zone are studied.The study shows that the quantitative method of reservoir flow field strength and the new well pattern adaptability evaluation method consisting of the control degree of remaining reserve and the flooding potential based on streamline distribution can consider reservoir heterogeneity effectively,and have important guiding significance for development adjustment of reservoir in extra-high water cut stage.